De-pressuring fuel system

[autobonrun]

I'm replacing some parts in my fuel system; namely the filter and the accumulator. Is there a good location to depressure the system in a controlled manner? I want to minimize spillage in the engine compartment.

[pete3799]

I just changed my fuel filter and held a rag under the lower fitting when i cracked it loose.
Not a lot of fuel came out.... but my car has been sitting all winter so there my not have been any residual pressure in the lines.

[newms]

It's not the pressure but the volume that's a challenge. Don't overthink it. Lots of paper towels shoved in there and go.

[adamr]

I used a mason jar, streamed perfectly into it when i took bottom fitting off filter.

[autobonrun]

Thanks. I'll probably just stick the towels in as you say and slowly crack a fitting. My real concern was replacing the accumulator since it is upstream from the filter and sees the entire system pressure. However, I guess enough towels should do the trick.

I did check my Bentley manual after posting and found a section on depressuring. It says to depressure the system by loosening the control pressure fitting at the distributor. I think the other thing I'll do while working on the fuel system is disconnect the battery to reduce any chance of a spark and leave it disconnect until the fumes have time to dissipate.

One additional question I have since I'm doing both filter and accumulator. There is also a control pressure regulator in the circuit. Which really holds the system pressure once you turn the car off; the accumulator, regulator, or both?

My car sometimes is difficult to crank after running so I was replacing the accumulator. Perhaps I should replace the regulator as well while I'm working on the system.

[boyt911sc]

Originally Posted by autobonrun

Thanks. I'll probably just stick the towels in as you say and slowly crack a fitting. My real concern was replacing the accumulator since it is upstream from the filter and sees the entire system pressure. However, I guess enough towels should do the trick.

I did check my Bentley manual after posting and found a section on depressuring. It says to depressure the system by loosening the control pressure fitting at the distributor. I think the other thing I'll do while working on the fuel system is disconnect the battery to reduce any chance of a spark and leave it disconnect until the fumes have time to dissipate.

One additional question I have since I'm doing both filter and accumulator. There is also a control pressure regulator in the circuit. Which really holds the system pressure once you turn the car off; the accumulator, regulator, or both?

My car sometimes is difficult to crank after running so I was replacing the accumulator. Perhaps I should replace the regulator as well while I'm working on the system.

autobonrun,

Unless the FP is running, then you should consider fuel spillage. After a prolong shutdown, the residual fuel pressure is very low that you could not even measure the residual pressure after 8 hours or longer. Paper towels or rags will do the work.

You could test the FA. It would take less than a minute to evaluate an FA. Why would you replace CIS components when you don't even know they are bad unless you want to spend unnecessarily. Your problem is probably low residual fuel pressure. There are several culprits that could cause this problem. One is the FA. Others are FP check valve and FD return valve. You could investigate which one is the culprit to save some money or simply buy all the parts and replace them. It is your money. Spend it the way you like it.

Why would you break the fitting at the distributor to depressurize the line? It does not make sense. What ever residual pressure (low) remaining in the fuel lines will be present in the system. Just make it simple. You want to replace the fuel filter, then break the fitting at the fuel filter or accumulator. Keep the disconnected fuel lines up higher to minimize fuel spillage. The total fuel coming out would just a few ounces. Keep us posted.

Tony